Adaptation to Visual Motion in Directional Neurons of the Nucleus of the Optic Tract

1998 ◽  
Vol 79 (3) ◽  
pp. 1481-1493 ◽  
Author(s):  
Michael R. Ibbotson ◽  
Colin W. G. Clifford ◽  
Richard F. Mark
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Firing Rate ◽  
Visual Motion ◽  
Temporal Frequency ◽  
Optic Tract ◽  
Resolving Power ◽  
Adaptation Period ◽  
Time Constants ◽  
Preferred Direction

Ibbotson, Michael R., Colin W. G. Clifford, and Richard F. Mark. Adaptation to visual motion in directional neurons of the nucleus of the optic tract. J. Neurophysiol. 79: 1481–1493, 1998. Extracellular recordings of action potentials were made from directional neurons in the nucleus of the optic tract (NOT) of the wallaby, Macropus eugenii, while stimulating with moving sine-wave gratings. When a grating was moved at a constant velocity in the preferred direction through a neuron's receptive field, the firing rate increased rapidly and then declined exponentially until reaching a steady-state level. The decline in response is called motion adaptation. The rate of adaptation increased as the temporal frequency of the drifting grating increased, up to the frequency that elicited the maximum firing rate. Beyond this frequency, the adaptation rate decreased. When the adapting grating's spatial frequency was varied, such that response magnitudes were significantly different, the maximum adaptation rate occurred at similar temporal frequencies. Hence the temporal frequency of the stimulus is a major parameter controlling the rate of adaptation. In most neurons, the temporal frequency response functions measured after adaptation were shifted to the right when compared with those obtained in the unadapted state. Further insight into the adaptation process was obtained by measuring the responses of the cells to grating displacements within one frame (10.23 ms). Such impulsive stimulus movements of less than a one-quarter cycle elicited a response that rose rapidly to a maximum and then declined exponentially to the spontaneous firing rate in several seconds. The level of adaptation was demonstrated by observing how the time constants of the exponentials varied as a function of the temporal frequency of a previously presented moving grating. When plotted as functions of adapting frequency, time constants formed a U-shaped curve. The shortest time constants occurred at similar temporal frequencies, regardless of changes in spatial frequency, even when the change in spatial frequency resulted in large differences in response magnitude during the adaptation period. The strongest adaptation occurred when the adapting stimulus moved in the neuron's preferred direction. Stimuli that moved in the antipreferred direction or flickered had an adapting influence on the responses to subsequent impulsive movements, but the effect was far smaller than that elicited by preferred direction adaptation. Adaptation in one region of the receptive field did not affect the responses elicited by subsequent stimulation in nonoverlapping regions of the field. Adaptation is a significant property of NOT neurons and probably acts to expand their temporal resolving power.

scholarly journals Feedback from V1 and inhibition from beyond the classical receptive field modulates the responses of neurons in the primate lateral geniculate nucleus

2002 ◽  
Vol 19 (5) ◽  
pp. 583-592 ◽  
Author(s):  
BEN S. WEBB ◽  
CHRIS J. TINSLEY ◽  
NICK E. BARRACLOUGH ◽  
ALEXANDER EASTON ◽  
AMANDA PARKER ◽  
...  
Keyword(s):  
Receptive Field ◽  
Firing Rate ◽  
Lateral Geniculate Nucleus ◽  
Visual Information ◽  
Striate Cortex ◽  
Temporal Frequency ◽  
Optimal Size ◽  
Marmoset Monkey ◽  
Lateral Geniculate ◽  
Classical Receptive Field

It is well established that the responses of neurons in the lateral geniculate nucleus (LGN) can be modulated by feedback from visual cortex, but it is still unclear how cortico-geniculate afferents regulate the flow of visual information to the cortex in the primate. Here we report the effects, on the gain of LGN neurons, of differentially stimulating the extraclassical receptive field, with feedback from the striate cortex intact or inactivated in the marmoset monkey, Callithrix jacchus. A horizontally oriented grating of optimal size, spatial frequency, and temporal frequency was presented to the classical receptive field. The grating varied in contrast (range: 0–1) from trial to trial, and was presented alone, or surrounded by a grating of the same or orthogonal orientation, contained within either a larger annular field, or flanks oriented either horizontally or vertically. V1 was ablated to inactivate cortico-geniculate feedback. The maximum firing rate of LGN neurons was greater with V1 intact, but was reduced by visually stimulating beyond the classical receptive field. Large horizontal or vertical annular gratings were most effective in reducing the maximum firing rate of LGN neurons. Magnocellular neurons were most susceptible to this inhibition from beyond the classical receptive field. Extraclassical inhibition was less effective with V1 ablated. We conclude that inhibition from beyond the classical receptive field reduces the excitatory influence of V1 in the LGN. The net balance between cortico-geniculate excitation and inhibition from beyond the classical receptive field is one mechanism by which signals relayed from the retina to V1 are controlled.

Spatial and temporal properties of neurons of the lateral suprasylvian cortex of the cat

1986 ◽  
Vol 56 (4) ◽  
pp. 969-986 ◽  
Author(s):  
M. C. Morrone ◽  
M. Di Stefano ◽  
D. C. Burr
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Second Harmonic ◽  
Temporal Frequency ◽  
Field Size ◽  
Contrast Threshold ◽  
Receptive Field Size ◽  
Contrast Gain ◽  
Lateral Suprasylvian Cortex ◽  
Suprasylvian Cortex

Neurons in the posteromedial lateral suprasylvian cortex (PMLS) of cats were recorded extracellularly to investigate their response to stimulation by bars and by sinusoidal gratings. Two general types of cells were identified: those that modulated in synchrony with the passage of drifting bars and gratings and those that responded with an unmodulated increase in discharge. Both types responded to contrast reversed gratings with a modulation of activity: the cells that modulated to drifting gratings modulated to the first harmonic of contrast reversed gratings (at appropriate spatial phase and frequency), whereas those that did not modulate to drifting gratings always modulated to the second harmonic of contrast reversed gratings. No cell had a clear null point. Nearly all cells were selective for spatial frequency. The preferred frequency ranged from 0.1 to 1 cycles per degree (cpd), and selectivity bandwidths (full width at half height) were around two octaves. Preferred spatial frequency was not correlated with receptive field size, but bandwidth and receptive field size were positively correlated. Preferred spatial frequency decreased with eccentricity, at about 0.05 octaves/deg. The response of all cells increased as a function of grating contrast up to a saturation level. The contrast threshold for response to a grating of optimal parameters was approximately 1% for most cells and the saturation contrast approximately 10%. The contrast gain was approximately 25 spikes/s per log unit of contrast. All cells were tuned for temporal frequency, preferring frequencies from approximately 3 to 10 Hz, with a selectivity bandwidth approximately 2 octaves. For some cells, the spatial selectivity did not depend on the temporal frequency and vice versa. Others were spatiotemporally coupled, with the preferred temporal frequency being lower at high than at low spatial frequencies, and the preferred spatial frequency lower at high than at low temporal frequencies. Previous results showing broad velocity tuning to a bar were replicated and found to be predictable from the combined spatial and temporal tuning of PMLS cells and the Fourier spectrum of a bar. Preferred temporal frequency steadily decreased with eccentricity, at 0.025 octaves/deg. The results for PMLS cells are compared with those of other visual areas. Acuity and spatial preference and selectivity bandwidth is comparable to all areas except area 17, where they are a factor of about two higher. Temporal selectivity in PMLS is as fine as observed in other areas. The possibility that PMLS cells may be involved with motion detection and detection of motion in depth is discussed.

Direction-Selective Neurons in the Optokinetic System With Long-Lasting After-Responses

2002 ◽  
Vol 88 (5) ◽  
pp. 2224-2231 ◽  
Author(s):  
Nicholas S. C. Price ◽  
Michael R. Ibbotson
Keyword(s):  
Temporal Frequency ◽  
Optic Tract ◽  
Movement Control ◽  
Oscillatory Behavior ◽  
Head Movements ◽  
Functional Roles ◽  
Preferred Direction ◽  
Spatial Frequencies ◽  
Pretectal Nucleus ◽  
Motion Detectors

We describe the responses during and after motion of slow cells, which are a class of direction-selective neurons in the pretectal nucleus of the optic tract (NOT) of the wallaby. Neurons in the NOT respond to optic flow generated by head movements and drive compensatory optokinetic eye movements. Motion in the preferred direction produces increased firing rates in the cells, whereas motion in the opposite direction inhibits their high spontaneous activities. Neurons were stimulated with moving spatial sinusoidal gratings through a range of temporal and spatial frequencies. The slow cells were maximally stimulated at temporal frequencies <1 Hz and spatial frequencies of 0.13–1 cpd. During motion, the responses oscillate at the fundamental temporal frequency of the grating but not at higher-order harmonics. There is prolonged excitation after preferred direction motion and prolonged inhibition after anti-preferred direction motion, which are referred to as same-sign after-responses (SSARs). This is the first time that the response properties of neurons with SSARs have been reported and modeled in detail for neurons in the NOT. Slow cell responses during and after motion are modeled using an array of Reichardt-type motion detectors that include band-pass temporal prefilters. The oscillatory behavior during motion and the SSARs can be simulated accurately with the model by manipulating time constants associated with temporal filtering in the prefilters and motion detectors. The SSARs of slow cells are compared with those of previously described direction-selective neurons, which usually show transient inhibition or excitation after preferred or anti-preferred direction motion, respectively. Possible functional roles for slow cells are discussed in the context of eye movement control.

Inhibition and Excitation in the Locust DCMD Receptive Field: Spatial Frequency, Temporal and Spatial Characteristics

1979 ◽  
Vol 80 (1) ◽  
pp. 191-216
Author(s):  
ROBERT B. PINTER
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Visual Angle ◽  
Temporal Frequency ◽  
Low Frequency ◽  
Movement Detector ◽  
Small Target ◽  
Grating Pattern ◽  
Spatial Frequencies ◽  
Pattern Size

1. The descending contralateral movement detector (DCMD) of the locust responds vigorously to small target (ca. 5°) stimuli; this response is inhibited by simultaneous or subsequent rotation of a radial grating (windmill) pattern (subtending 19-90° of visual angle) and suppressed by earlier rotation. 2. The excitation produced in the DCMD by rotation of a radial grating pattern depends only on the spatial frequency of the stripes of the pattern, and is independent of pattern size, and of temporal frequency over the range of low values used. 3. The inhibition produced by this same stimulus similarly depends only on the spatial frequency of the stripes of the pattern, independent of pattern size, and of temporal frequency over the range of low values used. 4. As the radial grating excitation decreases with increasing spatial frequency, the inhibition increases until limited by optical and neural resolution. 5. For spatial frequencies of the radial grating pattern below 0.05 cyc/deg the radial grating patterns become excitatory. Above 0.05 cyc/deg they are inhibitory. This is the point in spatial frequency below which inhibitory grating ‘backgrounds’ become excitatory targets. 6. Inhibition decreases as the size of the radial grating pattern is decreased below 190 visual angle; at 8° or less no inhibition can be found at any spatial frequency. 7. Inhibition is greater in the posterior than anterior regions of the receptive field, and greater in the ventral than the dorsal regions. 8. Inhibition decreases as the distance between small target and the radial grating is increased, but this is influenced by the local variations of excitation and inhibition. 9. Habituation is often greater for small target and low-frequency radial grating response than for inhibited small target and high frequency grating response. 10. These results substantiate previously proposed lateral inhibition models of the acridid movement detector system.

Response to Motion in Extrastriate Area MSTl: Center-Surround Interactions

1998 ◽  
Vol 80 (1) ◽  
pp. 282-296 ◽  
Author(s):  
Satoshi Eifuku ◽  
Robert H. Wurtz
Keyword(s):  
Receptive Field ◽  
Opposite Direction ◽  
Visual Motion ◽  
Stimulus Presentation ◽  
Macaque Monkey ◽  
Object Motion ◽  
Temporal Area ◽  
Field Center ◽  
Preferred Direction ◽  
Receptive Field Center

Eifuku, Satoshi and Robert H. Wurtz. Response to motion in extrastriate area MSTl: center-surround interactions. J. Neurophysiol. 80: 282–296, 1998. The medial superior temporal area of the macaque monkey extrastriate visual cortex can be divided into a dorsal medial (MSTd) and a lateral ventral (MSTl) region. The functions of the two regions may not be identical: MSTd may process optic flow information that results from the movement of the observer, whereas MSTl may be related more closely to processing visual motion related specifically to the motion of objects. If MSTl were related to such object motion, one would expect to see mechanisms for the segregation of objects from their surround. We investigated one of these mechanisms in MSTl neurons: the effect of stimuli falling in the region surrounding the receptive field center on the response to stimuli falling in the field center. We found the effects of the surround stimulation to be modulatory with little response to the surround stimulus itself but a clear effect on the response to the stimulus falling on the receptive field center. The response to motion in the center in the direction preferred for the neuron usually increased when the surround motion was in the opposite direction to that in the center and decreased when surround motion was in the same direction as that in the center. Fifty-seven percent of the neurons showed a ratio of response for center motion with a surround moving in the opposite direction to that in the center for center motion alone that was >1. The response to motion in the center also increased when the surround stimulus was stationary, and this increase was sometimes larger than that with a moving surround. Nearly 70% of the neurons showed a ratio of response to center motion with a stationary surround to center motion alone that was >1. This is in contrast to the minimal effect of stationary surrounds in middle temporal area neurons. When the stimulus presentation was reversed so that the stimulus in the center was stationary and the surround moved, some MSTl neurons responded when the direction of motion in the surround was in the direction opposite to the preferred direction of motion in the center of the receptive field. Stimulation of the surround thus had a profound effect on the response of MSTl neurons, and this pronounced effect of the surround is consistent with a role in the segmentation of objects using motion.

scholarly journals The Roles of Different Spatial Frequency Channels in Real-World Visual Motion Perception

2018 ◽  
Author(s):  
Cong Shi ◽  
Shrinivas Pundlik ◽  
Gang Luo
Keyword(s):  
Spatial Frequency ◽  
Motion Perception ◽  
Visual Motion ◽  
Low Vision ◽  
Estimation Error ◽  
Temporal Frequency ◽  
Speed Estimation ◽  
Cutoff Frequencies ◽  
Vision Condition ◽  
Speed Perception

AbstractSpeed perception is an important task performed by our visual system in various daily life tasks. In various psychophysical tests, relationship between spatial frequency, temporal frequency, and speed has been examined in human subjects. The role of vision impairment in speed perception has also been previously examined. In this work, we examine the inter-relationship between speed, spatial frequency, low vision conditions, and the type of input motion stimuli in motion perception accuracy. For this purpose, we propose a computational model for speed perception and evaluate it in custom generated natural and stochastic sequences by simulating low-vision conditions (low pass filtering at different cutoff frequencies) as well as complementary vision conditions (high pass versions at the same cutoff frequencies). Our results show that low frequency components are critical for accurate speed perception, whereas high frequencies do not play any important role in speed estimation. Since perception of low frequencies may not be impaired in visual acuity loss, speed perception was not found to be impaired in low vision conditions compared to normal vision condition. We also report significant differences between natural and stochastic stimuli, notably an increase in speed estimation error when using stochastic stimuli compared to natural sequences, emphasizing the use of natural stimuli when performing future psychophysical studies for speed perception.

p-Chloroamphetamine treatment modifies evoked responses to sinusoidal gratings in the pigeon optic tectum

1989 ◽  
Vol 2 (2) ◽  
pp. 147-152 ◽  
Author(s):  
R. Alesci ◽  
V. Porciatti ◽  
L. Sebastiani ◽  
P. Bagnoli
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Optic Tectum ◽  
Temporal Frequency ◽  
Evoked Responses ◽  
Sinusoidal Gratings ◽  
Selective Depletion ◽  
Hydroxyindoleacetic Acid ◽  
Serotonergic Function ◽  
Tectal Neurons

AbstractThis study was performed in order to establish whether selective depletion of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the pigeon optic tectum (TeO) induced by p-chloroamphetamine (p-CA) modified tectal evoked potentials (TEPs). TEPs in response to sinusoidal gratings of different contrast, spatial and temporal frequency were recorded in control pigeons and in pigeons intraperitoneally injected with p-CA (10 mg/kg; two administrations in consecutive days). TEPs of p-CA treated pigeons, as compared to those of control pigeons, were reduced in amplitude as a function of contrast, spatial and temporal frequency. In addition, TEPs of p-CA treated pigeons differed from those recorded in controls in their transfer characteristics of contrast and spatial frequency. In particular, TEPs of p-CA treated pigeons did not saturate at moderate contrast, unlike those of controls. Furthermore, the TEP spatial tuning in p-CA treated pigeons is broader than that in controls; it thus suggests a reduction of spatial-frequency selectivity. These findings indicate that a selective neurotoxin for serotonergic systems, such as p-CA, can serve as a useful denervation tool for the study of the serotonergic function in the pigeon TeO. In addition, selective changes of TEP properties suggest the possibility that serotonergic afferents play a modulatory role on the receptive-field characteristics of tectal neurons.

scholarly journals Calcium accumulation in visual interneurons of the fly: stimulus dependence and relationship to membrane potential

1995 ◽  
Vol 73 (6) ◽  
pp. 2540-2552 ◽  
Author(s):  
M. Egelhaaf ◽  
A. Borst
Keyword(s):  
Membrane Potential ◽  
Synaptic Input ◽  
Calcium Concentration ◽  
Visual Motion ◽  
Temporal Frequency ◽  
Dendritic Tree ◽  
Calcium Signal ◽  
Calcium Accumulation ◽  
Preferred Direction ◽  
Pattern Motion

1. The large motion-sensitive tangential neurons in the fly third visual neuropil spatially pool the postsynaptic signals of many local elements. The changes in membrane potential and calcium concentration induced in these cells by visual motion are analyzed in vivo by simultaneous optical and intracellular voltage recording techniques. 2. Visual motion in the preferred direction leads to depolarization of the cell and to calcium accumulation mainly in the axon terminal, the soma, and the dendritic tree. During motion in the null direction, the cell hyperpolarizes and virtually no changes in calcium concentration can be observed. 3. Dendritic calcium accumulation is first restricted to those dendritic branches that are close to the sites of direct synaptic input. In other parts of the dendrite the calcium concentration increases more slowly and usually reaches only lower levels. 4. Calcium starts accumulating at the onset of motion. However, the calcium concentration reaches its final steady-state level much later than the corresponding membrane potential changes. Even if these are completely transient at high temporal frequencies of pattern motion, the calcium signal stays high until the stimulus pattern stops moving. 5. The amplitude of the calcium signal depends on the temporal frequency of pattern motion in a similar way as do the corresponding membrane potential changes. However, there exist differences that can be attributed to the different time courses of both signals. 6. Depolarization of the dendritic tree by current injection through a microelectrode leads to similar changes in calcium accumulation as does activation by synaptic input, suggesting that calcium enters the cell via voltage-dependent channels. The possible function of calcium channels for dendritic integration of synaptic input is discussed.

scholarly journals Compound stimuli reveal the structure of visual motion selectivity in macaque MT neurons

2019 ◽  
Author(s):  
Andrew D Zaharia ◽  
Robbe L T Goris ◽  
J Anthony Movshon ◽  
Eero P Simoncelli
Keyword(s):  
Spatial Frequency ◽  
Moving Objects ◽  
Visual Motion ◽  
Temporal Frequency ◽  
Direction Selectivity ◽  
Local Motion ◽  
Area Mt ◽  
Mt Neurons ◽  
Tilted Plane ◽  
Local Edge

AbstractMotion selectivity in primary visual cortex (V1) is approximately separable in orientation, spatial frequency, and temporal frequency (“frequency-separable”). Models for area MT neurons posit that their selectivity arises by combining direction-selective V1 afferents whose tuning is organized around a tilted plane in the frequency domain, specifying a particular direction and speed (“velocity-separable”). This construction explains “pattern direction selective” MT neurons, which are velocity-selective but relatively invariant to spatial structure, including spatial frequency, texture and shape. Surprisingly, when tested with single drifting gratings, most MT neurons’ responses are fit equally well by models with either form of separability. However, responses to plaids (sums of two moving gratings) tend to be better described as velocity-separable, especially for pattern neurons. We conclude that direction selectivity in MT is primarily computed by summing V1 afferents, but pattern-invariant velocity tuning for complex stimuli may arise from local, recurrent interactions.Significance StatementHow do sensory systems build representations of complex features from simpler ones? Visual motion representation in cortex is a well-studied example: the direction and speed of moving objects, regardless of shape or texture, is computed from the local motion of oriented edges. Here we quantify tuning properties based on single-unit recordings in primate area MT, then fit a novel, generalized model of motion computation. The model reveals two core properties of MT neurons — speed tuning and invariance to local edge orientation — result from a single organizing principle: each MT neuron combines afferents that represent edge motions consistent with a common velocity, much as V1 simple cells combine thalamic inputs consistent with a common orientation.

An adaptive Reichardt detector model of motion adaptation in insects and mammals

1997 ◽  
Vol 14 (4) ◽  
pp. 741-749 ◽  
Author(s):  
Colin W.G. Clifford ◽  
Michael R. Ibbotson ◽  
Keith Langley
Keyword(s):  
Dynamic Range ◽  
Frequency Tuning ◽  
Temporal Frequency ◽  
Optic Tract ◽  
Intrinsic Property ◽  
Wide Field ◽  
Motion Adaptation ◽  
Motion Sensitivity ◽  
Differential Motion ◽  
Motion Detectors

AbstractThere are marked similarities in the adaptation to motion observed in wide-field directional neurons found in the mammalian nucleus of the optic tract and cells in the insect lobula plate. However, while the form and time scale of adaptation is comparable in the two systems, there is a difference in the directional properties of the effect. A model based on the Reichardt detector is proposed to describe adaptation in mammals and insects, with only minor modifications required to account for the differences in directionality. Temporal-frequency response functions of the neurons and the model are shifted laterally and compressed by motion adaptation. The lateral shift enhances dynamic range and differential motion sensitivity. The compression is not caused by fatigue, but is an intrinsic property of the adaptive process resulting from interdependence of temporal-frequency tuning and gain in the temporal filters of the motion detectors.

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